Once a user participates in an event, the user evaluates their expectations of the event with their realisation of the event. This point, where the user tempers their expectations with their realisations, we call this point experience.
However, before the user will participate in an event, three factors guide their participation:
What does the user want?
How do they try to achieve that want? What’s their course of action?
What do they expect to happen?
These actions happen in a chronological sequence: one, two, three.
The user has an idea about something they want or need.
They have an idea about a course of action, and
They have an expectation that this course of action will let them fulfill their want or need.
I find it useful to envision this as a conversation.
The user has an idea for something they want. This is their goal. Since this is an idea they have, we’ll illustrate this as a lightbulb.
In a conversation, they think of something they can say that will get them closer to this thing they want. I call this “message,” so we’ll use a dialogue bubble to represent this.
Finally, they have an expectation of what will happen. I’ll use a stack of coins to illustrate what the user expects to receive.
An expectation can’t be formulated without a message (course of action), and the message (course of action) can’t be formulated without the initial goal. We can illustrate this by expressing our sequence of events as a simple equation:
The goal, message, and expectation constitute the user’s mental model. All of this takes place in the user’s mind, so we’ll finish things up by placing it all inside a thought-bubble above our humble little user’s head (his name is Ulysses Xavier).
The user’s mental model is an important aspect of user-centered design. But user-centered design’s chief conceit is that it’s not about users, but context, and not only the context of use, but the user’s mental context.
The user’s mental model describes the mental context, but we still don’t have the full picture. The mental model operates in context with both the event the user participates in (a conversation, driving a car, browsing a website) and the user’s personal information space (see Dan Brown’s diagram of personal information spaces). The personal information space is a nebulous cloud of facts, tidbits, and rules the user leverages to choose goals, devise messages (courses of action), and formulate expectations.